You should have 2 appointments,
at least in Boston it is requested.
BTW, they ask us to keep appontment time,
but they really serve people FIFO.
So you will be waiting as everybody else without an appointment.
We had an appontment time 11:00 a.m.,
and we were there about 10:40 a.m.
and got tickets, where was written "your waiting time 3 hours"
After 2 hours of wating we were called...
I asked IIO :Why we have to schedule appontment if we are in the same line,
as everybody else without appointment,
the answer was - we will not serve you without appointments...
BCIS is as usual very-very bad
at least in Boston.